Mass Changes When A Reactant Or Product Is A Gas (GCSE Chemistry)

When a metal reacts with oxygen in a sealed container (no matter leaves), what happens to the total mass of the sealed container and contents?

If a student collects 20.0 cm3 of gas at RTP in a measuring cylinder, how many moles of gas is this? (24 dm3 = 24 000 cm3 per mole)

If 2.00 g carbon burns to CO2 and all the oxygen comes from the air, what is the mass of the CO2 produced? (Ar C = 12, O = 16)

When magnesium ribbon burns in air to form magnesium oxide the measured mass of the sample increases. Why?

A carbonate reacts with acid producing 0.10 mol CO2 that escapes. What volume (in dm3) does this gas occupy at room temperature and pressure (24 dm3 per mole)?

1.00 g of magnesium is burned in oxygen to make magnesium oxide. (Ar: Mg = 24.3, O = 16.0) What is the increase in mass of the sample due to oxygen combining with the magnesium?

Which of the following best describes the change in measured mass when a gas reactant is consumed in an open container?

A student collects gas from a reaction into an inverted measuring cylinder but fails to fill the trough with water high enough so some gas escapes. How will the experimentally measured mass change compare with the theoretical mass change?

A reaction produces gas that is dissolved in the liquid rather than escaping. If later the liquid is heated and gas evolves, what will an open-balance measurement show while gas is dissolved and then after heating?

A student measures the mass of a beaker + contents before and after a reaction that produces hydrogen gas which is collected. The measured mass decreases by 0.016 g. Which statement best explains the change?

Which method ensures the mass of a reacting system remains constant during a reaction that produces gas so students can easily demonstrate conservation of mass?